Roof of buildings



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Nov. 5, 1935. F. BAsTEN ET A1.

ROOF oF BUILDINGS Filed March 1'7, 1954 AT TO R N EVS N O0/W E -R @u TNmEN ADE BRV Um MH WN LV DL im ,ME

Patented Nov. 5, 1935 uien STATES 'PATENT OFFICEA ROOF OF BUILDINGSApplication March 17, 1934, Serial No. 716,026 In Great Britain March21, 1933 4 Claims.

invention relates to roofs of buildings and in particular to flat roofs.

For many years flat roofs were covered with metal, which had thedisadvantage of involving considerable expense in the construction ofthe roof timbers and was unsuitable to withstand traine, and further themetal roofing could not be easily applied to concrete structures. Rockasphalt was also extensively adopted. for flat roof covering, ut owingto its rigid nature was very liable to crack. Neither of these coveringshad any heat insulating properties.

Built up layers of waterproof felt and bitumen as a waterproofing forflat roofs have also been l5 extensively used, but tol ensure reasonabledurability and to comply with building laws and regulations and therequirements of fire insurance companies, some protective covering hadto be provided. Various kinds of protective coverings have been appliedover the felt and bitumen, which were subject to some disadvantage,either that they did not strictly comply with the building laws, or ifthey did, they were of such a dense nature that considerable heat wastransmitted to the sub-structure. In many cases the protective coveringswere not suitable for traic, and invariably they absorbed heat from thesun and transferred it to the supporting structure, which expanded andcontracted, thereby disturbing the walls of the building, and. also thetemperature of the space below the roof was liable to excessivevariations.

The object of the invention is to provide a protective covering whichwill (1) comply strictly with all building by-laws and fire insuranceregulations, (2) give the maximum external insulation by reflection ofthe suns rays, (3) present a surface which can be used for balconies,sun balconies of hospitals, tea pavillons and like structures wherechairs and tables or beds can be freely used, (4) have a pleasing andattractive appearance.

According to the invention, the protective covering consists of flattiles of rigid insoluble and incombustible material such as porousconcrete with a facing of asbestos cement, which tiles when applied tothe roof are bedded in bitumen. The asbestos cement is preferably turnedround the edges of the tiles and carried on the underside of the tiles,say for about one inch, to prevent the percolation of water from theedges into the concrete, permitting the tiles to be laid with slightlyopen joints to allow for expansion Without disturbance. The tiles arepreferably grooved on their underside to take up any excess of bitumen.

These tiles having a, practicallyv impervious asbestos cement facingwith a porous backing are light in weight and of high insulatingqualities. They will withstand any ordinary traffic on the roof andretain their light grey surface per- 5 manently, presenting the maximumreflection of the suns rays at all times-even after rain-thus givingperfect insulation to the substructure and the rooms beneath. Althoughthe tiles, which are of relatively small size, say l2 inches indiameter, 10 are practically impervious unless exposed to very heavy andlong-continued rain, they are not intended for the purpose lofincreasing the weather-resisting qualities of the roof, this being thefunction vof the existing bituminous layer or 15 layers underneath them,which they protect and insulate. The filling must be rigid and strongenough to support the asbestos cement facing against traflic, for whichpurpose wood is unsuitable b-ut porous concrete is suitable. 20

In order that the said invention may be clearly understood and readilycarried into effect, the same will now be further described withreference to the accompanying drawing, which is a perspective View of aportion of a flat roof ex- 25 emplifying the invention.

A indicates wood planks forming a part of a fiat roof, B layers ofwaterproof fabric, C tiles each comprising a porous back D of anydesired thickness, for example of porous concrete, and 30 a facing E ofasbestos cement, which gives a hard tough wearing surface practicallyimpervious to moisture, and at each of its four edges is turned inunderneath the concrete or other incombustible and insoluble porousbacking ma- 35 terial. Grooves, not shown, may be provided in the saidbacking material, not for keying purposes, but to receive any surpluslbitumen that may be squeezed up. Although the invention is described andillustrated as applied to a hat o roof of wooden construction, it willreadily be understood that the invention can be equally well applied toconcrete or hollow tiles or any other form of flat roof.

What we claim and desire to secure by Letters 45 Patent of the UnitedStates is:-

1. A flat heat insulating rectangular tile of uniform thickness adap-tedfor covering flat roofs to withstand traffic thereon, said tileconsisting of a filling of a uniformly solid and rigid insoluble 50incombustible material of great inherent strength such as porousconcrete, and a facing of asbestos cement on. the upper side of saidfilling, the asbestos cement being turned down at all the four edges ofthe filling and turned inward for a short distance underneath thefilling at all the said four edges, which asbestos cement facing servesto protect the filling and forms a heat insulation preventing passage ofheat to said filling.

2. A fiat heat insulating roofing tile of uniform thickness adapted forcovering flat roofs to withstand traiiic thereon, said tile consistingof a filling of a uniformly solid and rigid insoluble incornbustiblematerial of great inherent strength such as porous concrete, and afacing of asbestos cement on the upper side of said lling, the asbestoscement being turned down at the peripheral edges all around the fillingand turned inward for a uniformly short distance beneath said filling atsaid peripheral edges, which asbestos cementv facing serves to protectthe filling and forms a heat insulation preventing passage of heat tosaid filling.

3. A heat insulating flat roof comprising, in combination, a support,waterproof fabric laid on said support, a bituminous coating over saidfabric, and a plurality of tiles embedded in said coating and slightlyspaced apart to permit of expansion and' contraction, each of whichtiles is of flat rectangular form and of uniform thickness, andcomprises a filling of a uniformly solid and rigid insolubleincombustible material of great inherent strength such as porousconcrete, and a heat insulating facing of asbestos cement on the upperside of said filling, serving to insulate and protect said filling fromradiant heat the asbestos cement being turned down at al1 the four edgesof the filling and turned inward for a short distance underneath thefilling at all the said four edges so as to expose the interior fillingof concrete of each tile Within the edges upon the bottom thereofdirectly to the underlying bituminous coating, said bituminous coatingextending a limited distance upward in the spaces between the tiles andserving to seal the same and the filling of said tiles against theatmosphere and other influences.

4. A heat insulating flat roof comprising, in combination, a. support,waterproof fabric laid on said support, a bituminous coating over saidfabric, and a plurality of tiles embedded in said coating and slightlyspaced apart to permit of expansion and contraction, each" of whichtileis iiat and of uniform thickness, and comp-rises tile of uniformthickness adapted for covering flat roofs to withstand tra-flic thereon,said tile consisting of a filling of a uniformly solid and rigidinsoluble incombustible material of great inherent strength such asporous concrete, and a heat insulating facing of asbestos cement on theupper side of said filling, serving to insulate and protect said fillingfrom radiant heat the asbestos cement being turned'down at theperipheral edges all around the filling and turned inward for auniformly short distance beneath said lling at said peripheral edges soas to expose the interior filling of concrete of each tile within theedges upon the bottom thereof directly to the underlying bituminouscoating, said bituminous coating extending a limited distance upward inthe spaces between the tiles and serving to seal the same and thefilling of said tiles against the atmosphere and other influences.

FREDERICK BASTEN. EVELYN HURDEN.

